xref: /linux/drivers/mmc/host/meson-gx-mmc.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
1 /*
2  * Amlogic SD/eMMC driver for the GX/S905 family SoCs
3  *
4  * Copyright (c) 2016 BayLibre, SAS.
5  * Author: Kevin Hilman <khilman@baylibre.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  * The full GNU General Public License is included in this distribution
19  * in the file called COPYING.
20  */
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/device.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/ioport.h>
28 #include <linux/spinlock.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/mmc/host.h>
31 #include <linux/mmc/mmc.h>
32 #include <linux/mmc/sdio.h>
33 #include <linux/mmc/slot-gpio.h>
34 #include <linux/io.h>
35 #include <linux/clk.h>
36 #include <linux/clk-provider.h>
37 #include <linux/regulator/consumer.h>
38 #include <linux/interrupt.h>
39 #include <linux/bitfield.h>
40 
41 #define DRIVER_NAME "meson-gx-mmc"
42 
43 #define SD_EMMC_CLOCK 0x0
44 #define   CLK_DIV_MASK GENMASK(5, 0)
45 #define   CLK_DIV_MAX 63
46 #define   CLK_SRC_MASK GENMASK(7, 6)
47 #define   CLK_SRC_XTAL 0   /* external crystal */
48 #define   CLK_SRC_XTAL_RATE 24000000
49 #define   CLK_SRC_PLL 1    /* FCLK_DIV2 */
50 #define   CLK_SRC_PLL_RATE 1000000000
51 #define   CLK_CORE_PHASE_MASK GENMASK(9, 8)
52 #define   CLK_TX_PHASE_MASK GENMASK(11, 10)
53 #define   CLK_RX_PHASE_MASK GENMASK(13, 12)
54 #define   CLK_PHASE_0 0
55 #define   CLK_PHASE_90 1
56 #define   CLK_PHASE_180 2
57 #define   CLK_PHASE_270 3
58 #define   CLK_ALWAYS_ON BIT(24)
59 
60 #define SD_EMMC_DElAY 0x4
61 #define SD_EMMC_ADJUST 0x8
62 #define SD_EMMC_CALOUT 0x10
63 #define SD_EMMC_START 0x40
64 #define   START_DESC_INIT BIT(0)
65 #define   START_DESC_BUSY BIT(1)
66 #define   START_DESC_ADDR_MASK GENMASK(31, 2)
67 
68 #define SD_EMMC_CFG 0x44
69 #define   CFG_BUS_WIDTH_MASK GENMASK(1, 0)
70 #define   CFG_BUS_WIDTH_1 0x0
71 #define   CFG_BUS_WIDTH_4 0x1
72 #define   CFG_BUS_WIDTH_8 0x2
73 #define   CFG_DDR BIT(2)
74 #define   CFG_BLK_LEN_MASK GENMASK(7, 4)
75 #define   CFG_RESP_TIMEOUT_MASK GENMASK(11, 8)
76 #define   CFG_RC_CC_MASK GENMASK(15, 12)
77 #define   CFG_STOP_CLOCK BIT(22)
78 #define   CFG_CLK_ALWAYS_ON BIT(18)
79 #define   CFG_CHK_DS BIT(20)
80 #define   CFG_AUTO_CLK BIT(23)
81 
82 #define SD_EMMC_STATUS 0x48
83 #define   STATUS_BUSY BIT(31)
84 
85 #define SD_EMMC_IRQ_EN 0x4c
86 #define   IRQ_EN_MASK GENMASK(13, 0)
87 #define   IRQ_RXD_ERR_MASK GENMASK(7, 0)
88 #define   IRQ_TXD_ERR BIT(8)
89 #define   IRQ_DESC_ERR BIT(9)
90 #define   IRQ_RESP_ERR BIT(10)
91 #define   IRQ_RESP_TIMEOUT BIT(11)
92 #define   IRQ_DESC_TIMEOUT BIT(12)
93 #define   IRQ_END_OF_CHAIN BIT(13)
94 #define   IRQ_RESP_STATUS BIT(14)
95 #define   IRQ_SDIO BIT(15)
96 
97 #define SD_EMMC_CMD_CFG 0x50
98 #define SD_EMMC_CMD_ARG 0x54
99 #define SD_EMMC_CMD_DAT 0x58
100 #define SD_EMMC_CMD_RSP 0x5c
101 #define SD_EMMC_CMD_RSP1 0x60
102 #define SD_EMMC_CMD_RSP2 0x64
103 #define SD_EMMC_CMD_RSP3 0x68
104 
105 #define SD_EMMC_RXD 0x94
106 #define SD_EMMC_TXD 0x94
107 #define SD_EMMC_LAST_REG SD_EMMC_TXD
108 
109 #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */
110 #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */
111 #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */
112 #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */
113 #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
114 #define SD_EMMC_DESC_BUF_LEN PAGE_SIZE
115 
116 #define SD_EMMC_PRE_REQ_DONE BIT(0)
117 #define SD_EMMC_DESC_CHAIN_MODE BIT(1)
118 
119 #define MUX_CLK_NUM_PARENTS 2
120 
121 struct meson_tuning_params {
122 	u8 core_phase;
123 	u8 tx_phase;
124 	u8 rx_phase;
125 };
126 
127 struct sd_emmc_desc {
128 	u32 cmd_cfg;
129 	u32 cmd_arg;
130 	u32 cmd_data;
131 	u32 cmd_resp;
132 };
133 
134 struct meson_host {
135 	struct	device		*dev;
136 	struct	mmc_host	*mmc;
137 	struct	mmc_command	*cmd;
138 
139 	spinlock_t lock;
140 	void __iomem *regs;
141 	struct clk *core_clk;
142 	struct clk_mux mux;
143 	struct clk *mux_clk;
144 	unsigned long current_clock;
145 
146 	struct clk_divider cfg_div;
147 	struct clk *cfg_div_clk;
148 
149 	unsigned int bounce_buf_size;
150 	void *bounce_buf;
151 	dma_addr_t bounce_dma_addr;
152 	struct sd_emmc_desc *descs;
153 	dma_addr_t descs_dma_addr;
154 
155 	struct meson_tuning_params tp;
156 	bool vqmmc_enabled;
157 };
158 
159 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
160 #define CMD_CFG_BLOCK_MODE BIT(9)
161 #define CMD_CFG_R1B BIT(10)
162 #define CMD_CFG_END_OF_CHAIN BIT(11)
163 #define CMD_CFG_TIMEOUT_MASK GENMASK(15, 12)
164 #define CMD_CFG_NO_RESP BIT(16)
165 #define CMD_CFG_NO_CMD BIT(17)
166 #define CMD_CFG_DATA_IO BIT(18)
167 #define CMD_CFG_DATA_WR BIT(19)
168 #define CMD_CFG_RESP_NOCRC BIT(20)
169 #define CMD_CFG_RESP_128 BIT(21)
170 #define CMD_CFG_RESP_NUM BIT(22)
171 #define CMD_CFG_DATA_NUM BIT(23)
172 #define CMD_CFG_CMD_INDEX_MASK GENMASK(29, 24)
173 #define CMD_CFG_ERROR BIT(30)
174 #define CMD_CFG_OWNER BIT(31)
175 
176 #define CMD_DATA_MASK GENMASK(31, 2)
177 #define CMD_DATA_BIG_ENDIAN BIT(1)
178 #define CMD_DATA_SRAM BIT(0)
179 #define CMD_RESP_MASK GENMASK(31, 1)
180 #define CMD_RESP_SRAM BIT(0)
181 
182 static unsigned int meson_mmc_get_timeout_msecs(struct mmc_data *data)
183 {
184 	unsigned int timeout = data->timeout_ns / NSEC_PER_MSEC;
185 
186 	if (!timeout)
187 		return SD_EMMC_CMD_TIMEOUT_DATA;
188 
189 	timeout = roundup_pow_of_two(timeout);
190 
191 	return min(timeout, 32768U); /* max. 2^15 ms */
192 }
193 
194 static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
195 {
196 	if (cmd->opcode == MMC_SET_BLOCK_COUNT && !cmd->error)
197 		return cmd->mrq->cmd;
198 	else if (mmc_op_multi(cmd->opcode) &&
199 		 (!cmd->mrq->sbc || cmd->error || cmd->data->error))
200 		return cmd->mrq->stop;
201 	else
202 		return NULL;
203 }
204 
205 static void meson_mmc_get_transfer_mode(struct mmc_host *mmc,
206 					struct mmc_request *mrq)
207 {
208 	struct mmc_data *data = mrq->data;
209 	struct scatterlist *sg;
210 	int i;
211 	bool use_desc_chain_mode = true;
212 
213 	/*
214 	 * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been
215 	 * reported. For some strange reason this occurs in descriptor
216 	 * chain mode only. So let's fall back to bounce buffer mode
217 	 * for command SD_IO_RW_EXTENDED.
218 	 */
219 	if (mrq->cmd->opcode == SD_IO_RW_EXTENDED)
220 		return;
221 
222 	for_each_sg(data->sg, sg, data->sg_len, i)
223 		/* check for 8 byte alignment */
224 		if (sg->offset & 7) {
225 			WARN_ONCE(1, "unaligned scatterlist buffer\n");
226 			use_desc_chain_mode = false;
227 			break;
228 		}
229 
230 	if (use_desc_chain_mode)
231 		data->host_cookie |= SD_EMMC_DESC_CHAIN_MODE;
232 }
233 
234 static inline bool meson_mmc_desc_chain_mode(const struct mmc_data *data)
235 {
236 	return data->host_cookie & SD_EMMC_DESC_CHAIN_MODE;
237 }
238 
239 static inline bool meson_mmc_bounce_buf_read(const struct mmc_data *data)
240 {
241 	return data && data->flags & MMC_DATA_READ &&
242 	       !meson_mmc_desc_chain_mode(data);
243 }
244 
245 static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
246 {
247 	struct mmc_data *data = mrq->data;
248 
249 	if (!data)
250 		return;
251 
252 	meson_mmc_get_transfer_mode(mmc, mrq);
253 	data->host_cookie |= SD_EMMC_PRE_REQ_DONE;
254 
255 	if (!meson_mmc_desc_chain_mode(data))
256 		return;
257 
258 	data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len,
259                                    mmc_get_dma_dir(data));
260 	if (!data->sg_count)
261 		dev_err(mmc_dev(mmc), "dma_map_sg failed");
262 }
263 
264 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
265 			       int err)
266 {
267 	struct mmc_data *data = mrq->data;
268 
269 	if (data && meson_mmc_desc_chain_mode(data) && data->sg_count)
270 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
271 			     mmc_get_dma_dir(data));
272 }
273 
274 static int meson_mmc_clk_set(struct meson_host *host, unsigned long clk_rate)
275 {
276 	struct mmc_host *mmc = host->mmc;
277 	int ret;
278 	u32 cfg;
279 
280 	if (clk_rate) {
281 		if (WARN_ON(clk_rate > mmc->f_max))
282 			clk_rate = mmc->f_max;
283 		else if (WARN_ON(clk_rate < mmc->f_min))
284 			clk_rate = mmc->f_min;
285 	}
286 
287 	if (clk_rate == host->current_clock)
288 		return 0;
289 
290 	/* stop clock */
291 	cfg = readl(host->regs + SD_EMMC_CFG);
292 	if (!(cfg & CFG_STOP_CLOCK)) {
293 		cfg |= CFG_STOP_CLOCK;
294 		writel(cfg, host->regs + SD_EMMC_CFG);
295 	}
296 
297 	dev_dbg(host->dev, "change clock rate %u -> %lu\n",
298 		mmc->actual_clock, clk_rate);
299 
300 	if (!clk_rate) {
301 		mmc->actual_clock = 0;
302 		host->current_clock = 0;
303 		/* return with clock being stopped */
304 		return 0;
305 	}
306 
307 	ret = clk_set_rate(host->cfg_div_clk, clk_rate);
308 	if (ret) {
309 		dev_err(host->dev, "Unable to set cfg_div_clk to %lu. ret=%d\n",
310 			clk_rate, ret);
311 		return ret;
312 	}
313 
314 	mmc->actual_clock = clk_get_rate(host->cfg_div_clk);
315 	host->current_clock = clk_rate;
316 
317 	if (clk_rate != mmc->actual_clock)
318 		dev_dbg(host->dev,
319 			"divider requested rate %lu != actual rate %u\n",
320 			clk_rate, mmc->actual_clock);
321 
322 	/* (re)start clock */
323 	cfg = readl(host->regs + SD_EMMC_CFG);
324 	cfg &= ~CFG_STOP_CLOCK;
325 	writel(cfg, host->regs + SD_EMMC_CFG);
326 
327 	return 0;
328 }
329 
330 /*
331  * The SD/eMMC IP block has an internal mux and divider used for
332  * generating the MMC clock.  Use the clock framework to create and
333  * manage these clocks.
334  */
335 static int meson_mmc_clk_init(struct meson_host *host)
336 {
337 	struct clk_init_data init;
338 	char clk_name[32];
339 	int i, ret = 0;
340 	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
341 	const char *clk_div_parents[1];
342 	u32 clk_reg, cfg;
343 
344 	/* get the mux parents */
345 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
346 		struct clk *clk;
347 		char name[16];
348 
349 		snprintf(name, sizeof(name), "clkin%d", i);
350 		clk = devm_clk_get(host->dev, name);
351 		if (IS_ERR(clk)) {
352 			if (clk != ERR_PTR(-EPROBE_DEFER))
353 				dev_err(host->dev, "Missing clock %s\n", name);
354 			return PTR_ERR(clk);
355 		}
356 
357 		mux_parent_names[i] = __clk_get_name(clk);
358 	}
359 
360 	/* create the mux */
361 	snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev));
362 	init.name = clk_name;
363 	init.ops = &clk_mux_ops;
364 	init.flags = 0;
365 	init.parent_names = mux_parent_names;
366 	init.num_parents = MUX_CLK_NUM_PARENTS;
367 	host->mux.reg = host->regs + SD_EMMC_CLOCK;
368 	host->mux.shift = __bf_shf(CLK_SRC_MASK);
369 	host->mux.mask = CLK_SRC_MASK;
370 	host->mux.flags = 0;
371 	host->mux.table = NULL;
372 	host->mux.hw.init = &init;
373 
374 	host->mux_clk = devm_clk_register(host->dev, &host->mux.hw);
375 	if (WARN_ON(IS_ERR(host->mux_clk)))
376 		return PTR_ERR(host->mux_clk);
377 
378 	/* create the divider */
379 	snprintf(clk_name, sizeof(clk_name), "%s#div", dev_name(host->dev));
380 	init.name = clk_name;
381 	init.ops = &clk_divider_ops;
382 	init.flags = CLK_SET_RATE_PARENT;
383 	clk_div_parents[0] = __clk_get_name(host->mux_clk);
384 	init.parent_names = clk_div_parents;
385 	init.num_parents = ARRAY_SIZE(clk_div_parents);
386 
387 	host->cfg_div.reg = host->regs + SD_EMMC_CLOCK;
388 	host->cfg_div.shift = __bf_shf(CLK_DIV_MASK);
389 	host->cfg_div.width = __builtin_popcountl(CLK_DIV_MASK);
390 	host->cfg_div.hw.init = &init;
391 	host->cfg_div.flags = CLK_DIVIDER_ONE_BASED |
392 		CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ALLOW_ZERO;
393 
394 	host->cfg_div_clk = devm_clk_register(host->dev, &host->cfg_div.hw);
395 	if (WARN_ON(PTR_ERR_OR_ZERO(host->cfg_div_clk)))
396 		return PTR_ERR(host->cfg_div_clk);
397 
398 	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
399 	clk_reg = 0;
400 	clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, host->tp.core_phase);
401 	clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, host->tp.tx_phase);
402 	clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, host->tp.rx_phase);
403 	clk_reg |= FIELD_PREP(CLK_SRC_MASK, CLK_SRC_XTAL);
404 	clk_reg |= FIELD_PREP(CLK_DIV_MASK, CLK_DIV_MAX);
405 	clk_reg &= ~CLK_ALWAYS_ON;
406 	writel(clk_reg, host->regs + SD_EMMC_CLOCK);
407 
408 	/* Ensure clock starts in "auto" mode, not "always on" */
409 	cfg = readl(host->regs + SD_EMMC_CFG);
410 	cfg &= ~CFG_CLK_ALWAYS_ON;
411 	cfg |= CFG_AUTO_CLK;
412 	writel(cfg, host->regs + SD_EMMC_CFG);
413 
414 	ret = clk_prepare_enable(host->cfg_div_clk);
415 	if (ret)
416 		return ret;
417 
418 	/* Get the nearest minimum clock to 400KHz */
419 	host->mmc->f_min = clk_round_rate(host->cfg_div_clk, 400000);
420 
421 	ret = meson_mmc_clk_set(host, host->mmc->f_min);
422 	if (ret)
423 		clk_disable_unprepare(host->cfg_div_clk);
424 
425 	return ret;
426 }
427 
428 static void meson_mmc_set_tuning_params(struct mmc_host *mmc)
429 {
430 	struct meson_host *host = mmc_priv(mmc);
431 	u32 regval;
432 
433 	/* stop clock */
434 	regval = readl(host->regs + SD_EMMC_CFG);
435 	regval |= CFG_STOP_CLOCK;
436 	writel(regval, host->regs + SD_EMMC_CFG);
437 
438 	regval = readl(host->regs + SD_EMMC_CLOCK);
439 	regval &= ~CLK_CORE_PHASE_MASK;
440 	regval |= FIELD_PREP(CLK_CORE_PHASE_MASK, host->tp.core_phase);
441 	regval &= ~CLK_TX_PHASE_MASK;
442 	regval |= FIELD_PREP(CLK_TX_PHASE_MASK, host->tp.tx_phase);
443 	regval &= ~CLK_RX_PHASE_MASK;
444 	regval |= FIELD_PREP(CLK_RX_PHASE_MASK, host->tp.rx_phase);
445 	writel(regval, host->regs + SD_EMMC_CLOCK);
446 
447 	/* start clock */
448 	regval = readl(host->regs + SD_EMMC_CFG);
449 	regval &= ~CFG_STOP_CLOCK;
450 	writel(regval, host->regs + SD_EMMC_CFG);
451 }
452 
453 static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
454 {
455 	struct meson_host *host = mmc_priv(mmc);
456 	u32 bus_width;
457 	u32 val, orig;
458 
459 	/*
460 	 * GPIO regulator, only controls switching between 1v8 and
461 	 * 3v3, doesn't support MMC_POWER_OFF, MMC_POWER_ON.
462 	 */
463 	switch (ios->power_mode) {
464 	case MMC_POWER_OFF:
465 		if (!IS_ERR(mmc->supply.vmmc))
466 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
467 
468 		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
469 			regulator_disable(mmc->supply.vqmmc);
470 			host->vqmmc_enabled = false;
471 		}
472 
473 		break;
474 
475 	case MMC_POWER_UP:
476 		if (!IS_ERR(mmc->supply.vmmc))
477 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
478 		break;
479 
480 	case MMC_POWER_ON:
481 		if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
482 			int ret = regulator_enable(mmc->supply.vqmmc);
483 
484 			if (ret < 0)
485 				dev_err(mmc_dev(mmc),
486 					"failed to enable vqmmc regulator\n");
487 			else
488 				host->vqmmc_enabled = true;
489 		}
490 
491 		break;
492 	}
493 
494 
495 	meson_mmc_clk_set(host, ios->clock);
496 
497 	/* Bus width */
498 	switch (ios->bus_width) {
499 	case MMC_BUS_WIDTH_1:
500 		bus_width = CFG_BUS_WIDTH_1;
501 		break;
502 	case MMC_BUS_WIDTH_4:
503 		bus_width = CFG_BUS_WIDTH_4;
504 		break;
505 	case MMC_BUS_WIDTH_8:
506 		bus_width = CFG_BUS_WIDTH_8;
507 		break;
508 	default:
509 		dev_err(host->dev, "Invalid ios->bus_width: %u.  Setting to 4.\n",
510 			ios->bus_width);
511 		bus_width = CFG_BUS_WIDTH_4;
512 	}
513 
514 	val = readl(host->regs + SD_EMMC_CFG);
515 	orig = val;
516 
517 	val &= ~CFG_BUS_WIDTH_MASK;
518 	val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width);
519 
520 	val &= ~CFG_DDR;
521 	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
522 	    ios->timing == MMC_TIMING_MMC_DDR52 ||
523 	    ios->timing == MMC_TIMING_MMC_HS400)
524 		val |= CFG_DDR;
525 
526 	val &= ~CFG_CHK_DS;
527 	if (ios->timing == MMC_TIMING_MMC_HS400)
528 		val |= CFG_CHK_DS;
529 
530 	if (val != orig) {
531 		writel(val, host->regs + SD_EMMC_CFG);
532 		dev_dbg(host->dev, "%s: SD_EMMC_CFG: 0x%08x -> 0x%08x\n",
533 			__func__, orig, val);
534 	}
535 }
536 
537 static void meson_mmc_request_done(struct mmc_host *mmc,
538 				   struct mmc_request *mrq)
539 {
540 	struct meson_host *host = mmc_priv(mmc);
541 
542 	host->cmd = NULL;
543 	mmc_request_done(host->mmc, mrq);
544 }
545 
546 static void meson_mmc_set_blksz(struct mmc_host *mmc, unsigned int blksz)
547 {
548 	struct meson_host *host = mmc_priv(mmc);
549 	u32 cfg, blksz_old;
550 
551 	cfg = readl(host->regs + SD_EMMC_CFG);
552 	blksz_old = FIELD_GET(CFG_BLK_LEN_MASK, cfg);
553 
554 	if (!is_power_of_2(blksz))
555 		dev_err(host->dev, "blksz %u is not a power of 2\n", blksz);
556 
557 	blksz = ilog2(blksz);
558 
559 	/* check if block-size matches, if not update */
560 	if (blksz == blksz_old)
561 		return;
562 
563 	dev_dbg(host->dev, "%s: update blk_len %d -> %d\n", __func__,
564 		blksz_old, blksz);
565 
566 	cfg &= ~CFG_BLK_LEN_MASK;
567 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, blksz);
568 	writel(cfg, host->regs + SD_EMMC_CFG);
569 }
570 
571 static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg)
572 {
573 	if (cmd->flags & MMC_RSP_PRESENT) {
574 		if (cmd->flags & MMC_RSP_136)
575 			*cmd_cfg |= CMD_CFG_RESP_128;
576 		*cmd_cfg |= CMD_CFG_RESP_NUM;
577 
578 		if (!(cmd->flags & MMC_RSP_CRC))
579 			*cmd_cfg |= CMD_CFG_RESP_NOCRC;
580 
581 		if (cmd->flags & MMC_RSP_BUSY)
582 			*cmd_cfg |= CMD_CFG_R1B;
583 	} else {
584 		*cmd_cfg |= CMD_CFG_NO_RESP;
585 	}
586 }
587 
588 static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
589 {
590 	struct meson_host *host = mmc_priv(mmc);
591 	struct sd_emmc_desc *desc = host->descs;
592 	struct mmc_data *data = host->cmd->data;
593 	struct scatterlist *sg;
594 	u32 start;
595 	int i;
596 
597 	if (data->flags & MMC_DATA_WRITE)
598 		cmd_cfg |= CMD_CFG_DATA_WR;
599 
600 	if (data->blocks > 1) {
601 		cmd_cfg |= CMD_CFG_BLOCK_MODE;
602 		meson_mmc_set_blksz(mmc, data->blksz);
603 	}
604 
605 	for_each_sg(data->sg, sg, data->sg_count, i) {
606 		unsigned int len = sg_dma_len(sg);
607 
608 		if (data->blocks > 1)
609 			len /= data->blksz;
610 
611 		desc[i].cmd_cfg = cmd_cfg;
612 		desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len);
613 		if (i > 0)
614 			desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
615 		desc[i].cmd_arg = host->cmd->arg;
616 		desc[i].cmd_resp = 0;
617 		desc[i].cmd_data = sg_dma_address(sg);
618 	}
619 	desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
620 
621 	dma_wmb(); /* ensure descriptor is written before kicked */
622 	start = host->descs_dma_addr | START_DESC_BUSY;
623 	writel(start, host->regs + SD_EMMC_START);
624 }
625 
626 static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
627 {
628 	struct meson_host *host = mmc_priv(mmc);
629 	struct mmc_data *data = cmd->data;
630 	u32 cmd_cfg = 0, cmd_data = 0;
631 	unsigned int xfer_bytes = 0;
632 
633 	/* Setup descriptors */
634 	dma_rmb();
635 
636 	host->cmd = cmd;
637 
638 	cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
639 	cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
640 
641 	meson_mmc_set_response_bits(cmd, &cmd_cfg);
642 
643 	/* data? */
644 	if (data) {
645 		data->bytes_xfered = 0;
646 		cmd_cfg |= CMD_CFG_DATA_IO;
647 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
648 				      ilog2(meson_mmc_get_timeout_msecs(data)));
649 
650 		if (meson_mmc_desc_chain_mode(data)) {
651 			meson_mmc_desc_chain_transfer(mmc, cmd_cfg);
652 			return;
653 		}
654 
655 		if (data->blocks > 1) {
656 			cmd_cfg |= CMD_CFG_BLOCK_MODE;
657 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK,
658 					      data->blocks);
659 			meson_mmc_set_blksz(mmc, data->blksz);
660 		} else {
661 			cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz);
662 		}
663 
664 		xfer_bytes = data->blksz * data->blocks;
665 		if (data->flags & MMC_DATA_WRITE) {
666 			cmd_cfg |= CMD_CFG_DATA_WR;
667 			WARN_ON(xfer_bytes > host->bounce_buf_size);
668 			sg_copy_to_buffer(data->sg, data->sg_len,
669 					  host->bounce_buf, xfer_bytes);
670 			dma_wmb();
671 		}
672 
673 		cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
674 	} else {
675 		cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK,
676 				      ilog2(SD_EMMC_CMD_TIMEOUT));
677 	}
678 
679 	/* Last descriptor */
680 	cmd_cfg |= CMD_CFG_END_OF_CHAIN;
681 	writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
682 	writel(cmd_data, host->regs + SD_EMMC_CMD_DAT);
683 	writel(0, host->regs + SD_EMMC_CMD_RSP);
684 	wmb(); /* ensure descriptor is written before kicked */
685 	writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
686 }
687 
688 static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
689 {
690 	struct meson_host *host = mmc_priv(mmc);
691 	bool needs_pre_post_req = mrq->data &&
692 			!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
693 
694 	if (needs_pre_post_req) {
695 		meson_mmc_get_transfer_mode(mmc, mrq);
696 		if (!meson_mmc_desc_chain_mode(mrq->data))
697 			needs_pre_post_req = false;
698 	}
699 
700 	if (needs_pre_post_req)
701 		meson_mmc_pre_req(mmc, mrq);
702 
703 	/* Stop execution */
704 	writel(0, host->regs + SD_EMMC_START);
705 
706 	meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
707 
708 	if (needs_pre_post_req)
709 		meson_mmc_post_req(mmc, mrq, 0);
710 }
711 
712 static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
713 {
714 	struct meson_host *host = mmc_priv(mmc);
715 
716 	if (cmd->flags & MMC_RSP_136) {
717 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP3);
718 		cmd->resp[1] = readl(host->regs + SD_EMMC_CMD_RSP2);
719 		cmd->resp[2] = readl(host->regs + SD_EMMC_CMD_RSP1);
720 		cmd->resp[3] = readl(host->regs + SD_EMMC_CMD_RSP);
721 	} else if (cmd->flags & MMC_RSP_PRESENT) {
722 		cmd->resp[0] = readl(host->regs + SD_EMMC_CMD_RSP);
723 	}
724 }
725 
726 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
727 {
728 	struct meson_host *host = dev_id;
729 	struct mmc_command *cmd;
730 	struct mmc_data *data;
731 	u32 irq_en, status, raw_status;
732 	irqreturn_t ret = IRQ_HANDLED;
733 
734 	if (WARN_ON(!host))
735 		return IRQ_NONE;
736 
737 	cmd = host->cmd;
738 
739 	if (WARN_ON(!cmd))
740 		return IRQ_NONE;
741 
742 	data = cmd->data;
743 
744 	spin_lock(&host->lock);
745 	irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
746 	raw_status = readl(host->regs + SD_EMMC_STATUS);
747 	status = raw_status & irq_en;
748 
749 	if (!status) {
750 		dev_warn(host->dev, "Spurious IRQ! status=0x%08x, irq_en=0x%08x\n",
751 			 raw_status, irq_en);
752 		ret = IRQ_NONE;
753 		goto out;
754 	}
755 
756 	meson_mmc_read_resp(host->mmc, cmd);
757 
758 	cmd->error = 0;
759 	if (status & IRQ_RXD_ERR_MASK) {
760 		dev_dbg(host->dev, "Unhandled IRQ: RXD error\n");
761 		cmd->error = -EILSEQ;
762 	}
763 	if (status & IRQ_TXD_ERR) {
764 		dev_dbg(host->dev, "Unhandled IRQ: TXD error\n");
765 		cmd->error = -EILSEQ;
766 	}
767 	if (status & IRQ_DESC_ERR)
768 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor error\n");
769 	if (status & IRQ_RESP_ERR) {
770 		dev_dbg(host->dev, "Unhandled IRQ: Response error\n");
771 		cmd->error = -EILSEQ;
772 	}
773 	if (status & IRQ_RESP_TIMEOUT) {
774 		dev_dbg(host->dev, "Unhandled IRQ: Response timeout\n");
775 		cmd->error = -ETIMEDOUT;
776 	}
777 	if (status & IRQ_DESC_TIMEOUT) {
778 		dev_dbg(host->dev, "Unhandled IRQ: Descriptor timeout\n");
779 		cmd->error = -ETIMEDOUT;
780 	}
781 	if (status & IRQ_SDIO)
782 		dev_dbg(host->dev, "Unhandled IRQ: SDIO.\n");
783 
784 	if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
785 		if (data && !cmd->error)
786 			data->bytes_xfered = data->blksz * data->blocks;
787 		if (meson_mmc_bounce_buf_read(data) ||
788 		    meson_mmc_get_next_command(cmd))
789 			ret = IRQ_WAKE_THREAD;
790 	} else {
791 		dev_warn(host->dev, "Unknown IRQ! status=0x%04x: MMC CMD%u arg=0x%08x flags=0x%08x stop=%d\n",
792 			 status, cmd->opcode, cmd->arg,
793 			 cmd->flags, cmd->mrq->stop ? 1 : 0);
794 		if (cmd->data) {
795 			struct mmc_data *data = cmd->data;
796 
797 			dev_warn(host->dev, "\tblksz %u blocks %u flags 0x%08x (%s%s)",
798 				 data->blksz, data->blocks, data->flags,
799 				 data->flags & MMC_DATA_WRITE ? "write" : "",
800 				 data->flags & MMC_DATA_READ ? "read" : "");
801 		}
802 	}
803 
804 out:
805 	/* ack all (enabled) interrupts */
806 	writel(status, host->regs + SD_EMMC_STATUS);
807 
808 	if (ret == IRQ_HANDLED)
809 		meson_mmc_request_done(host->mmc, cmd->mrq);
810 
811 	spin_unlock(&host->lock);
812 	return ret;
813 }
814 
815 static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
816 {
817 	struct meson_host *host = dev_id;
818 	struct mmc_command *next_cmd, *cmd = host->cmd;
819 	struct mmc_data *data;
820 	unsigned int xfer_bytes;
821 
822 	if (WARN_ON(!cmd))
823 		return IRQ_NONE;
824 
825 	data = cmd->data;
826 	if (meson_mmc_bounce_buf_read(data)) {
827 		xfer_bytes = data->blksz * data->blocks;
828 		WARN_ON(xfer_bytes > host->bounce_buf_size);
829 		sg_copy_from_buffer(data->sg, data->sg_len,
830 				    host->bounce_buf, xfer_bytes);
831 	}
832 
833 	next_cmd = meson_mmc_get_next_command(cmd);
834 	if (next_cmd)
835 		meson_mmc_start_cmd(host->mmc, next_cmd);
836 	else
837 		meson_mmc_request_done(host->mmc, cmd->mrq);
838 
839 	return IRQ_HANDLED;
840 }
841 
842 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
843 {
844 	struct meson_host *host = mmc_priv(mmc);
845 	struct meson_tuning_params tp_old = host->tp;
846 	int ret = -EINVAL, i, cmd_error;
847 
848 	dev_info(mmc_dev(mmc), "(re)tuning...\n");
849 
850 	for (i = CLK_PHASE_0; i <= CLK_PHASE_270; i++) {
851 		host->tp.rx_phase = i;
852 		/* exclude the active parameter set if retuning */
853 		if (!memcmp(&tp_old, &host->tp, sizeof(tp_old)) &&
854 		    mmc->doing_retune)
855 			continue;
856 		meson_mmc_set_tuning_params(mmc);
857 		ret = mmc_send_tuning(mmc, opcode, &cmd_error);
858 		if (!ret)
859 			break;
860 	}
861 
862 	return ret;
863 }
864 
865 /*
866  * NOTE: we only need this until the GPIO/pinctrl driver can handle
867  * interrupts.  For now, the MMC core will use this for polling.
868  */
869 static int meson_mmc_get_cd(struct mmc_host *mmc)
870 {
871 	int status = mmc_gpio_get_cd(mmc);
872 
873 	if (status == -ENOSYS)
874 		return 1; /* assume present */
875 
876 	return status;
877 }
878 
879 static void meson_mmc_cfg_init(struct meson_host *host)
880 {
881 	u32 cfg = 0;
882 
883 	cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
884 			  ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
885 	cfg |= FIELD_PREP(CFG_RC_CC_MASK, ilog2(SD_EMMC_CFG_CMD_GAP));
886 	cfg |= FIELD_PREP(CFG_BLK_LEN_MASK, ilog2(SD_EMMC_CFG_BLK_SIZE));
887 
888 	writel(cfg, host->regs + SD_EMMC_CFG);
889 }
890 
891 static const struct mmc_host_ops meson_mmc_ops = {
892 	.request	= meson_mmc_request,
893 	.set_ios	= meson_mmc_set_ios,
894 	.get_cd         = meson_mmc_get_cd,
895 	.pre_req	= meson_mmc_pre_req,
896 	.post_req	= meson_mmc_post_req,
897 	.execute_tuning = meson_mmc_execute_tuning,
898 };
899 
900 static int meson_mmc_probe(struct platform_device *pdev)
901 {
902 	struct resource *res;
903 	struct meson_host *host;
904 	struct mmc_host *mmc;
905 	int ret, irq;
906 
907 	mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
908 	if (!mmc)
909 		return -ENOMEM;
910 	host = mmc_priv(mmc);
911 	host->mmc = mmc;
912 	host->dev = &pdev->dev;
913 	dev_set_drvdata(&pdev->dev, host);
914 
915 	spin_lock_init(&host->lock);
916 
917 	/* Get regulators and the supported OCR mask */
918 	host->vqmmc_enabled = false;
919 	ret = mmc_regulator_get_supply(mmc);
920 	if (ret == -EPROBE_DEFER)
921 		goto free_host;
922 
923 	ret = mmc_of_parse(mmc);
924 	if (ret) {
925 		if (ret != -EPROBE_DEFER)
926 			dev_warn(&pdev->dev, "error parsing DT: %d\n", ret);
927 		goto free_host;
928 	}
929 
930 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
931 	host->regs = devm_ioremap_resource(&pdev->dev, res);
932 	if (IS_ERR(host->regs)) {
933 		ret = PTR_ERR(host->regs);
934 		goto free_host;
935 	}
936 
937 	irq = platform_get_irq(pdev, 0);
938 	if (!irq) {
939 		dev_err(&pdev->dev, "failed to get interrupt resource.\n");
940 		ret = -EINVAL;
941 		goto free_host;
942 	}
943 
944 	host->core_clk = devm_clk_get(&pdev->dev, "core");
945 	if (IS_ERR(host->core_clk)) {
946 		ret = PTR_ERR(host->core_clk);
947 		goto free_host;
948 	}
949 
950 	ret = clk_prepare_enable(host->core_clk);
951 	if (ret)
952 		goto free_host;
953 
954 	host->tp.core_phase = CLK_PHASE_180;
955 	host->tp.tx_phase = CLK_PHASE_0;
956 	host->tp.rx_phase = CLK_PHASE_0;
957 
958 	ret = meson_mmc_clk_init(host);
959 	if (ret)
960 		goto err_core_clk;
961 
962 	/* Stop execution */
963 	writel(0, host->regs + SD_EMMC_START);
964 
965 	/* clear, ack, enable all interrupts */
966 	writel(0, host->regs + SD_EMMC_IRQ_EN);
967 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_STATUS);
968 	writel(IRQ_EN_MASK, host->regs + SD_EMMC_IRQ_EN);
969 
970 	/* set config to sane default */
971 	meson_mmc_cfg_init(host);
972 
973 	ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
974 					meson_mmc_irq_thread, IRQF_SHARED,
975 					NULL, host);
976 	if (ret)
977 		goto err_div_clk;
978 
979 	mmc->caps |= MMC_CAP_CMD23;
980 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
981 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
982 	mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc);
983 	mmc->max_seg_size = mmc->max_req_size;
984 
985 	/* data bounce buffer */
986 	host->bounce_buf_size = mmc->max_req_size;
987 	host->bounce_buf =
988 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
989 				   &host->bounce_dma_addr, GFP_KERNEL);
990 	if (host->bounce_buf == NULL) {
991 		dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
992 		ret = -ENOMEM;
993 		goto err_div_clk;
994 	}
995 
996 	host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
997 		      &host->descs_dma_addr, GFP_KERNEL);
998 	if (!host->descs) {
999 		dev_err(host->dev, "Allocating descriptor DMA buffer failed\n");
1000 		ret = -ENOMEM;
1001 		goto err_bounce_buf;
1002 	}
1003 
1004 	mmc->ops = &meson_mmc_ops;
1005 	mmc_add_host(mmc);
1006 
1007 	return 0;
1008 
1009 err_bounce_buf:
1010 	dma_free_coherent(host->dev, host->bounce_buf_size,
1011 			  host->bounce_buf, host->bounce_dma_addr);
1012 err_div_clk:
1013 	clk_disable_unprepare(host->cfg_div_clk);
1014 err_core_clk:
1015 	clk_disable_unprepare(host->core_clk);
1016 free_host:
1017 	mmc_free_host(mmc);
1018 	return ret;
1019 }
1020 
1021 static int meson_mmc_remove(struct platform_device *pdev)
1022 {
1023 	struct meson_host *host = dev_get_drvdata(&pdev->dev);
1024 
1025 	mmc_remove_host(host->mmc);
1026 
1027 	/* disable interrupts */
1028 	writel(0, host->regs + SD_EMMC_IRQ_EN);
1029 
1030 	dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
1031 			  host->descs, host->descs_dma_addr);
1032 	dma_free_coherent(host->dev, host->bounce_buf_size,
1033 			  host->bounce_buf, host->bounce_dma_addr);
1034 
1035 	clk_disable_unprepare(host->cfg_div_clk);
1036 	clk_disable_unprepare(host->core_clk);
1037 
1038 	mmc_free_host(host->mmc);
1039 	return 0;
1040 }
1041 
1042 static const struct of_device_id meson_mmc_of_match[] = {
1043 	{ .compatible = "amlogic,meson-gx-mmc", },
1044 	{ .compatible = "amlogic,meson-gxbb-mmc", },
1045 	{ .compatible = "amlogic,meson-gxl-mmc", },
1046 	{ .compatible = "amlogic,meson-gxm-mmc", },
1047 	{}
1048 };
1049 MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
1050 
1051 static struct platform_driver meson_mmc_driver = {
1052 	.probe		= meson_mmc_probe,
1053 	.remove		= meson_mmc_remove,
1054 	.driver		= {
1055 		.name = DRIVER_NAME,
1056 		.of_match_table = of_match_ptr(meson_mmc_of_match),
1057 	},
1058 };
1059 
1060 module_platform_driver(meson_mmc_driver);
1061 
1062 MODULE_DESCRIPTION("Amlogic S905*/GX* SD/eMMC driver");
1063 MODULE_AUTHOR("Kevin Hilman <khilman@baylibre.com>");
1064 MODULE_LICENSE("GPL v2");
1065